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Chevron announces deal on Central Valley dairy digester


This is a more than 600,000-gallon biogas digester spread over several acres on a dairy outside of Bakersfield. Chevron is partnering with Brightmark Fund Holdings LLC to develop a similar facility in Chowchilla.

Chevron USA Inc. on Thursday announced an agreement with San Francisco-based Brightmark Fund Holdings LLC to fund a large dairy digester in Chowchilla that would produce renewable natural gas for fueling movement of goods across the Central Valley.

The deal expands the oil major's RNG portfolio and serves as the latest sign California ag waste will play a big role in California's rush to renewable energy.

Details were not disclosed, including production capacity and employment in construction or operation. But Chevron said it and other existing and pending agreements will bring to the company to about 10,000 million BTUs of RNG daily production, or a quarter of the company's 2030 goal.

More than 100 dairy digesters are now spread across the valley, subsidized by state grants and supported financially by the state's Low Carbon Fuel Standard. Many are in Kern, including some that received investments from Chevron.

Dairy digesters process cow manure to collect methane for injection into a natural gas pipeline. In a market considered to be in its infancy, dairy RNG is sold as renewable fuel to operators of diesel engines, including heavy-duty trucks that have proved hard to electrify.

Dairy biomethane ranks highly on a scale of fuels and activities deemed helpful to fighting climate change, and it is seen as having a carbon negative lifecycle. Methane from unprocessed manure otherwise vents to the atmosphere as an especially potent greenhouse gas.

The practice has attracted criticism from environmental advocates who say the state's support for dairy digesters encourages consolidation and incentivizes an intensive agricultural practice that pollutes the region's air and groundwater.

Brightmark founder and CEO Bob Powell said the company shares environmental groups' goal of reducing manure-related groundwater pollution. Eating cheese and drinking milk necessarily creates waste, he noted, asserting Brightmark achieves a better environmental outcome. The company estimates it has offset more than 150,000 tons of carbon dioxide, including from previous work with Chevron.

Powell described the project as being relevant to Kern County because it shows another Central Valley farming community receiving a sustainable, mutually beneficial energy deal. He noted that although dairy projects are highest priority, other ag operations hold promise in the field of waste-to-energy.

"In Kern County, anytime you've got farming, there's a great opportunity to create RNG out of waste farm," Powell said. He added the project in Chowchilla is scheduled to be operational in one to two years, and that the digester project at Vlot Calf Ranch is Brightmark's largest.

Andy Walz, president of Americas Fuels & Lubricants for Chevron USA, said the company has done a lot to increase its RNG portfolio in the last two years. The activity is economically viable for the company, he said, and "we believe it's the right thing to do."

Walz added in a news release, “Developing and delivering renewable natural gas with Brightmark and the Vlot Calf Ranch, once completed, demonstrates our commitment to working across critical sectors of the state’s economy to increase the supply of fuels with a lower lifecycle carbon intensity.”

In June 2019, Chevron USA announced a partnership with Visalia-based California Bioenergy LLC to help fund up to 18 dairy digesters in Kern, Kings and Tulare counties. The oil producer agreed to help market the RNG for consumption by trucks, buses and other heavy-duty equipment.